Insiders recall how absurd it became when the engineering teams became increasingly split over who did and didn’t have access to the real UI, despite needing to work together. Ganatra remembers having to sprint back and forth between rooms to serve as a secure translator between the two teams. “I would go into the room where the full UI was, then come back and draw the rough proportions on the whiteboard for the other engineers,” he recalls.

[…]

Though more engineers were eventually given access to the full-blown UI, Forstall’s team was never truly on the same page. In fact, in Grignon’s recollection, he had to go to extremes to work around the system to the point where he had to sit his own engineers next to one another with a curtain in between—one with full iPhone access, the other with Skankphone access—to debug the code.